The present invention relates in general to lighting devices based on light-emitting diodes (LEDs) and in particular to LED emitters for lamps that can replace conventional A-19 incandescent lamps.
Among traditional incandescent light bulbs, the A-19 lamp, having a mushroom-shaped glass bulb, is the most popular. The widest part of the light bulb generally has a diameter of 19/8 inches or 2⅜ of an inch. The bulbs often have a metal screw base for inserting into an electric socket. A popular size for the base is 26 mm for the E26 base. The incandescent light bulbs suffer from low energy efficiency and short lifetime as they produce more heat than light. As a result, alternative lighting sources have been develop to replace the incandescent light bulbs.
LEDs are a promising technology more energy efficient and longer-lasting than incandescent light bulbs and are already widely deployed for specific purposes, such as traffic signals and flashlights. However, the development of LED-based lamps for general illumination has run into various difficulties. Among these is the difficulty of mass-producing lamps that provide high power light at a wide-angle.
For example, conventional LED-based lamps for replacing the A-19 incandescent bulbs are limited in their brightness, often produce light at 40 W incandescent equivalent with a power consumption of, e.g., 7-9 Watts. In part due to the size limitation of the A-19 bulbs, it is difficult to provide high power wide-angle LED emitters that are suitable for A-19 bulb applications.
Therefore, there is a need for a multiple-LED emitter module that can provide high power and wide-angle light suitable for A-19 lamp or similar applications.